1. Field of the Invention
The invention relates to a semiconductor power module with at least one semiconductor power component on a carrier plate formed of metallized ceramic, and at least one heat pipe integrated in the semiconductor power module for distributing heat to be removed from the semiconductor power component over an area of a condensation zone of the heat pipe which is larger than the base area of the semiconductor power component.
2. Description of the Related Art
Such modules have power semiconductors which are assembled by a soldered-contact technique and are electrically insulated on a ceramic substrate serving as the carrier plate.
Such semiconductor power modules are known from German Published, Non-Prosecuted Application DE-OS No. 34 02 003. In that device, the integration of a heat pipe in the module is proposed in order to distribute the dissipation heat of a semiconductor power component over a larger substrate area and therefore to improve the heat transport from the semiconductor power component to a cooling surface (heat sink) through an electrically insulating substrate. All of the structures known from this publication relate to an integration of the heat pipe into the metallization of the substrate. However, Only relatively small vapor spaces are able to be provided there for the heat pipe, so that the heat transport performance is strictly limited. In addition, the fabrication of the proposed fine structures for capillaries and vapor spaces is not very simple.
British Pat. No. 20 39 416 discloses a semiconductor power module with a heat pipe which has a vapor space of sufficient size. In FIG. 2 of that patent, a construction is shown in which a ceramic substrate is provided with cavities and is formed as a heat pipe. However, in that case the heat transport must go from the semiconductor components into the vapor space through a ceramic layer. Better thermal coupling between the semiconductor components and the vapor space of a heat pipe is obtained in a construction according to FIG. 5. In this construction, holes are provided in the ceramic, into which the semiconductor components are inserted and which are therefore in direct contact with the vapor space of the heat pipe. However, this concept still has some shortcomings, especially with respect to the practical ability to produce a module with a sufficiently long life. For instance, with the given means for joining the semiconductor components to the substrate and with the working liquids mentioned, no material combination is possible which would not lead to corrosion after a short time. In addition, a good spreading of the heat is not provided by the heat transport to one end of the heat pipe.